System and method for transferring wireless network access passwords

ABSTRACT

The present disclosure provides an access node for transferring and/or assigning network passwords. The access node includes a first interface for sending and receiving communication of a first type to and from a first node operating in a wireless local area network (WLAN). The access node also includes a second interface for sending and receiving communication of a second type to and from a second node in a mobile network, such as a GSM/GPRS network. The access node further includes a short messaging service (SMS) module for sending and receiving SMS messages to the second node carrying an OTP allocated. The access node also includes a mechanism to verify a precondition before the OTP is sent to the second node.

REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/434,695 filed May 9, 2003, the contents of which are herebyincorporated by reference in their entirety.

RELATED APPLICATIONS

This application relates to U.S. Ser. No. 09/851,681, filed on May 8,2001, U.S. Ser. No. 10/277,759, filed on Oct. 22, 2002, U.S. Ser. No.10/302,137, filed on Nov. 22, 2002, and U.S. Ser. No. 10/302,589, filedon Nov. 22, 2002, all of which are commonly assigned and incorporatedherein by reference in their entirety.

BACKGROUND

The present invention relates generally to a communications system and,more particularly, to a system and method for transferring and/orassigning network passwords through short messages.

Wireless local area network (WLAN) has emerged as a mainstreamtechnology to support high-speed wireless data transfer in a localcoverage area. For example, a version of WLAN commonly known as IEEE802.11 has been increasing in popularity. The 802.11 based WLAN hasrapidly gained acceptance in public hotspots, enterprises and homes.Other types of WLANs currently exist and will likely continue to emerge.

Access to WLANs must often be controlled and/or authenticated to ensurethat only certain entities can connect to the network. One common way ofcontrolling and/or authenticating access to a network is through the useof a password and/or access code, hereinafter generically “password.”Passwords can be entity specific, such as a single user, or can beavailable for a group of entities such as a group of users in a commonworkplace.

What is needed, is a system and method that system and method forassigning and/or providing passwords to one or more entities to allowthen to access a wireless network.

SUMMARY

The present disclosure provides a system and method for transferringand/or assigning network passwords. In one embodiment, a new and uniqueaccess node is provided. The access node includes a first interface forsending and receiving communication of a first type to and from a firstnode operating in a wireless local area network (WLAN). The access nodealso includes a second interface for sending and receiving communicationof a second type to and from a second node in a mobile network, such asa GSM/GPRS network. The access node further includes a short messagingservice (SMS) module for sending and receiving SMS messages to thesecond node.

In another embodiment, a new and unique method for providing a one-timepassword (OTP) to allow access to a WLAN is provided. The methodincludes sending a first SMS message to a mobile unit operating in awireless network, the first SMS message including an identifier for anaccess node serving the WLAN. The method also includes receiving asecond SMS message from the mobile unit into the access node, the secondSMS message indicating a desire to access the WLAN. A third SMS messageis then sent to the mobile unit including the OTP. As a result, the WLANcan be accessed using the OTP.

In another embodiment, a new and unique method for providing a one-timepassword (OTP) to a WLAN client is provided. The method includes sendinga first SMS message to a mobile unit operating in a wireless network,the first SMS message including an identifier for an access node servingthe WLAN. The method also includes receiving a second SMS message fromthe mobile unit into the access node and checking for a predeterminedcondition associated with either the mobile unit or the wirelessnetwork. If the predetermined condition is met, the OTP is provided tothe mobile unit and used to access a WLAN service from the WLAN client.

In some embodiments, the predetermined condition is periodically checkedwhile the WLAN service is being provided to the WLAN client.

In another embodiment, a new and unique method for providing access to aWLAN is disclosed. The method includes sending a first message to amobile station operating in a wireless network, the first messageincluding an identifier for an access node serving the WLAN. A secondmessage is received from the mobile station and sent to an access nodevia the wireless network so that the access node can provide an accesscode for accessing the WLAN. The access code is received from the accessnode in a third message sent to the mobile station so that the WLAN canbe accessed using the access code.

In another embodiment, a new and unique method for providing a passwordto an internet device for using a WLAN is provided. The method includesreceiving an SMS message from a mobile station operating in a wirelessnetwork into an access controller serving the WLAN. A predeterminedcondition associated with the mobile station is checked, and if it ismet, the password is provided to the mobile station. An access requestis received from the internet node, the access request including thepassword, and the internet device is allowed to connect to an internetnode.

In another embodiment, a new and improved wireless server is provided.The wireless server includes a first module for performing SGSNfunctionality and including a Gd interface connected to an SMS node in aGSM/GPRS network. The wireless server also includes a second module forperforming WLAN functions on a WLAN and a third module for providingInternet access to a WLAN device connected to the WLAN. The wirelessserver also includes means for transferring, through the Gd interface, aOne-Time Password (OTP) to a mobile unit connected to a wirelessnetwork, receiving the OTP from the WLAN device for authentication, andconnecting the WLAN device to the Internet upon receipt of the OTP.

Many advantages of the present invention will become apparent to oneskilled in the art from the subsequent description and the appendedclaims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example network that can benefit from differentembodiments of the present invention.

FIG. 2 is a block diagram of an access node for implementing one or moredifferent embodiments of the present invention.

FIG. 3 is a simplified diagram of a network showing the flow of SMSmessages between the access node of FIG. 2 and a mobile station.

FIG. 4 is a signal flow diagram for authenticating the access node ofFIG. 2 for operating in a mobile network.

DETAILED DESCRIPTION

The present invention can be described by the embodiments given below.It is understood, however, that the embodiments below are not intendedto be limitations to the present invention, but are used to describeexamples for implementing the invention.

Referring now to FIG. 1, five different networks are shown—a firstnetwork 10 such as the Internet, a second network 12 such as the publicSignaling System 7 (SS7) network, a third network 14 such as a mobile(or cellular) network, and two wireless local area networks (WLANs) 16,18. For the sake of example, specific nodes in or between the fivenetworks will be further discussed, it being understood that differentnodes will be used for different types of networks. For example, aglobal system mobile (GSM) network and a code division multiple access(CDMA) network are both suitable examples of the network 14, but onlythe GSM network example will be continued in the present disclosure toavoid confusion. In furtherance of the example, packet-switched datasignals and message names will be described using general packet radioservice (GPRS) format. For example, short message service (SMS) is usedas a data transfer mechanism for implementing different embodiments ofthe present invention. Also, links in the GSM/GPRS network 14 commonlyuse Gb, Gr, Gc, Gd, Gs, Gn, Gp, and Gi type interfaces for carryingdifferent combinations of signaling information and data, although othertypes of interfaces can also or alternatively be used.

The GSM/GPRS network 14 includes a plurality of mobile stations 20,which are illustrated in the present example as a cellular telephone anda computer connected to a cellular telephone. Other examples includepersonal digital assistants, pagers, wired telephones, and other typesof communication devices being used in the network 14. The mobilestations 20 are connected to one or more base station transceivers(BTSs) and controllers (BSCs) 22 through a wireless link. A link is ageneric term to describe a mechanism for sharing information between twonodes. The BSCs 22 are connected through a link 24 to a Serving GPRSSupport Note (SGSN) 26. It is understood that the reference to links andnodes is simplified, and that many intermediate nodes and links arelikely to exist between those illustrated.

The SGSN 26 is connected to an SMS Interworking Mobile Switching Center(MSC)/Gateway MSC (SMS-IWMSC/SMS-GMSC) 28 through a link 30 which ispart of the SS7 network 12. The SMS-IWMSC/SMS-GMSC 28 is furtherconnected to an SMSC 32. The SGSN 26 is also connected to a homelocation register (HLR) 34 through a link 36 and a Gateway GPRS SupportNode (GGSN) 38 through a link 40. The GGSN 38 is also connected to theHLR 34 through a link 42. An access node 68, discussed in greater detailbelow, is connected to the HLR 34 and the SMS-IWMSC/SMS-GMSC 28 via asignaling gateway 44.

The signaling gateway 44 is connected to the Internet 10 through links46 and 48, and the GGSN 38 is connected to the Internet through a link50. In addition, a charging gateway/billing system 52 is connected tothe Internet 10 through a link 54.

The first and second WLANs 16, 18 include a plurality of WLAN clients60, which are illustrated in the present example as a personal digitalassistant and a mobile computer. The WLAN clients 60 in the first WLAN16 can be connected to an access point (AP) 62 through a wireless link.The AP 62 is connected to a router 64 through a link 66, which isfurther connected to an access node 68 through a link 70. The WLANclients 60 in the second WLAN 18 can be connected to an AP 72 through awireless link. The AP 72 is connected to a router 74 through a link 76,which is further connected to the access node 68 through a link 80.

The WLAN clients 60 include appropriate client hardware and software forinterfacing with the access node 68, including a WLAN Network InterfaceCard (NIC). Also, one or more of the WLAN clients include a subscriberinterface module, or SIM card. A SIM card is traditionally inserted intoGSM-enabled telephones and includes telephone account information. Forother embodiments, including non-GSM embodiments, the SIM cardrepresents any hardware and/or software module that provides account andsecurity information for using a subscribed network.

The access node 68 is connected to an Authentication, Authorization, andAccounting (AAA) server 86 through a link 88 and is also connected tothe Internet 10 through a link 90. Furthermore, a charginggateway/billing system 92 is connected to the Internet 10 through a link94.

In the present example, the access node 68 is derived from and sharesmuch of the functionality of a WAIN server as provided by TransatTechnologies of Southlake, Tex. The WAIN server is described inpresently incorporated U.S. application Ser. No. 09/851,681. Additionsand modifications to the WAIN server are discussed in greater detailbelow. It is understood, however, that the present invention is notlimited for use on a WAIN server, but can be used on different serversproduced by different manufacturers.

The access node 68 seamlessly integrates the WLANs 16, 18 with theGSM/GPRS mobile network 14 based on the GSM/GPRS authentication and acharging mechanism using a SIM card. In addition to WLAN controlfunctions, the access node 68 acts as a GPRS support node presentingstandard GPRS link interfaces to communicate with other GPRS nodes. Oneof the interfaces is the Gd between the access node 68 and theSMS-IWMSC/SMS-GMSC for SMS transfer. Since the access node 68 hassignaling links to the HLR 34 and the SMS-IWMSC/SMS-GMSC 28, thefunction of transmitting the OTP through SMS can be integrated.

The access node 68 is often installed in hotspots or an insecureenvironment. In order for the access node 68 to be a “trusted entity” ofthe mobile network 14, a mechanism for validating the access node by themobile network is provided. The present disclosure describes a methodthat the access node 68 can operate as a standard GSM/GPRS mobile sothat the access node itself can be authenticated by an authenticationnode of the mobile network 14. This would prevent an unauthorizedoperation by the access node 68 software.

The access node 68 acts as a combined SMS-mobile and SGSN. The accessnode 68 can receive an SMS message from a mobile carrying its MSISDN andsend an SMS message to the mobile carrying an assigned OTP for the WLANaccess. With this SMS translation function in the access node 68, aclient of the access node can send and receive SMS messages through asimple interface.

In some embodiments, the access node 68 is capable of integrating theWLANs 16, 18 into the GSM/GPRS mobile network 14. In addition to theconventional control requirements for the WLANs 16, 18, the access node68 acts as a combined SGSN and GGSN (Gateway GPRS Support Node)providing standard GPRS interfaces to the GPRS core network. Theseinterfaces include Gi to the Internet 10 for IP data interworking, Gr tothe HLR/AuC (Authentication Center) 34 for authentication andsubscription data downloading, Ga to a Charging Gateway (CG) 92 forcharging data transferring, Gn to an external GGSN (or SGSN) 38 forroaming and mobility handling, and Gd to an SMS-IWMSC/SMS-GMSC 28 forSMS transfer. The access node 68 can support GPRS authentication,session management and mobility handling for one or more of the WLANclients 60. In the present embodiment, all internet protocol (IP)interfaces are designed around the access node 68. For communicatingwith the SS7 network 12, the Signaling Gateway 44 converts the IP basedprotocols to the SS7 based protocols. In other embodiments, the accessnode 68 can include the functionality of the signaling gateway 44.

If the WLAN client 60 includes a SIM card, it can authenticate itselfusing conventional GSM/GPRS authentication procedures. The WLAN client60 (acting as a “client”) will be identified and verified through itsInternational Mobile Subscriber Identity (IMSI) and the securityinformation stored on the SIM card. The access node 68 acts as a SGSN inthe authentication procedure. Charging data will be generated in astandard ASN.1 format and transferred to a Charging Gateway of themobile network 14.

For non-SIM WLAN clients 60, a User ID/Password can be provided via SMSto a different mobile station (e.g., mobile station 20) that isSIM-enabled or is otherwise configured for SMS. The information can thenbe used to authenticate the non-SIM WLAN client. In this scenario, theaccess node 68 acts as a RADIUS Client forwarding the User ID/Passwordand accounting information to the AAA server 86. It is understood thatthe RADIUS protocol is only one example of a suitable protocol, andother protocols can be used.

In the present example, the GSM/GPRS mobile network 14 intends to offerWLAN access to WLAN clients 60 in the WLAN networks 16, 18. The mobilenetwork 14 may broadcast a SMS message to mobile stations attached toits network. The message announces the WLAN access via an OTP offering,which may include a prompt for a mobile phone number via a web interfaceand/or an SMS message to a designated access node to obtain an OTP foraccessing the WLAN. The WLAN service accessed via the assigned OTP canthereby be charged to a mobile phone account.

Alternatively, the mobile network 14 can elect to offer the one-timeWLAN access free of charge under a predetermined condition, such as longas the mobile station 20 stays attached to the operator's mobile network14. Other conditions include a type of service subscribed by the mobilestation 20, time, or date. It is understood that reference to the mobilestation 20 refers to a mobile unit in the mobile network 14, whilereference to the WLAN client 60 refers to a wireless unit in the WLANs16, 18. In some embodiments, a mobile station 20 and a WLAN client 60can be the very same mobile unit, or portions of the same mobile unit,operating (or capable of operating) in either or both networks.

Referring also to FIG. 2, if the mobile network 14 is going to offerservices based on predetermined criteria associated with the mobilestation 20, the access controller 68 must be able to verify that thecriteria has been satisfied. Continuing with the example that the mobilenetwork 14 offers free WLAN access when the mobile station 20 isattached to the mobile network, the access controller 68 must be able todetermine if the mobile station is in the mobile network 14. In thepresent embodiment, the access node 68 has a RADIUS client module 100for authentication capability, a SGSN/GGSN functionality module 102 forconnecting to the mobile network 14, and an IP interface 104 forconnecting to the Internet 10. In addition, the access node 68 includesan SMS mobile module 106 for allowing the access node to appear as asubscriber to the mobile network 14, a SIM interface module 108 forreceiving a SIM card 110, a mobile locator module 112 for performing theactions necessary for the predetermined criteria (the mobile station 20is attached to the wireless network 14, in the present example), and anOTP assignment module 114 for creating the OTP. These modules may beprovided by one or more electric circuit cards located on the accessnode 68, a software modification/addition of an existing access node, ora combination thereof. For example, the electric cards may includeprocessors, memory, bus interface devices, buffers, and appropriatesoftware, based on choice of design by one of ordinary skill in the art.The modules are clearly defined by their operation, discussed in greaterdetail below. It is understood that not all of the above-mentionedmodules are required in every embodiment, and some modules willinherently be different to accommodate different network and signalingrequirements.

In the present embodiment, the access node 68 can act, at least in part,as a mobile station to the mobile network 14. In the present example,the access node 68 will obtain a GSM/GPRS subscription and thecorresponding SIM card 110 from an operator of the mobile network 14. Insome embodiments, the access node 68 will obtain multiple SIM cards foruse with one or more mobile networks. As part of the subscription, anMSISDN will be assigned to the access node 68 in addition to an IMSI. Infurtherance of the present example, the service profile will include atleast SMS-MO and SMS-MT services. Before the access node 68 can send orreceive SMS, an attach request procedure is initiated from the SMSmobile module 106 of the access node 68, and a GSM/GPRS authenticationprocedure can then be carried out with an appropriate HLR/AuC (e.g., theHLR 34 of FIG. 1) through the SGSN/GGSN functionality module 102. TheGSN/GGSN functionality module 102 includes the necessary hardware and/orsoftware to perform the steps required by the mobile network 14 forperforming the present operations.

In the present example, the access node 68 needs to interrogate the HLR34 for the current location area of the mobile station 20 with theassociated MSISDN number. This is done through a MAP (Mobile ApplicationPart) message “sendRoutingInfoForShortMsg” including the mobilestation's MSISDN number, the same one used by the SMS GMSC 28 tointerrogate the HLR 34 via the C interface to retrieve routinginformation necessary to forward the short message. The HLR 34 willreturn an MSC or SGSN address, or both addresses, identifying the mobilestation's location area if the mobile station 20 is attached. If themobile station 20 is not attached, the HLR 34 will return errorinformation. It is understood that the mobile station 20 may haveattached through an MSC or an SGSN that does not belong to the mobilenetwork 14. Using the mobile locator module 112, the access node 68 cancompare the received MSC/SGSN address(es) with a pre-stored list todetermine whether the mobile station 20 is currently attached to themobile network 14.

If the mobile station 20 is attached to the mobile network 14, the OTPassignment module 114 will assign an OTP associated with the MSISDN andwill form an SMS-MO message including the OTP for the mobile station 20identified by the MSISDN. The SMS-MO message is sent to the mobilenetwork's SMS-IWMSC 28 via the Gd interface on the link 48, and then tothe associated SMSC 32. The SMSC 32 then forwards the SMS information inan SMS-MT message to the mobile station 20 attached in the mobilenetwork 14 and identified by the MSISDN. If the mobile network 14 is aGSM network but not GPRS enabled, the SMS transmission to/from theSMS-IWMSC/SMS-GMSC 28 can be through an E interface. In this case, theaccess node 68 and the Signaling Gateway 44 emulate an MSC/VLR forcommunicating with the SMS-IWMSC/SMS-GMSC 28.

At the same time, the access node 68 can send the assigned OTP to theAAA server 86 for subsequent RADIUS authentication for WLAN access. Itis understood that the mobile station 20 may be in a WLAN area served byanother access node, instead of the designated access node 68. TheRADIUS authentication requests from multiple access nodes can be sent tothe AAA Server 86. In some embodiments, the AAA Server 86 can becombined into the designated access node 68.

If the WLAN client 60 provides its mobile number on a web page promptedby a serving access node other than the designated access node 68 (theone to which the mobile station 20 sends an SMS), the serving accessnode can carry the same procedure, i.e. checking the mobile location,assigning and sending an OTP to the WLAN client 60 and the AAA server86.

In the present example, the one-time WLAN access can be charged based onSMS-MO CDRs (Call Detail Record) and SMS-MT CDRs generated by the accessnode 68 and the MSC 152 or SGSN 26 in the mobile network 14 for the OTPtransfer. If the mobile network 14 decides to offer the one-time WLANaccess for a defined duration (e.g. 30 minutes), the durationinformation can be stored in the AAA Server 86 associated with the OTPaccount. If the mobile network 14 operator would like the mobile station20 to stay attached to the mobile network 14 during the free WLANservice period, the access node 68 can periodically interrogate the HLR34 for the location (and attachment status) of the mobile station 20.

Transmitting and receiving an SMS message on a WLAN client 60 terminalcan be performed by an SMS translation function of the access node 68.The WLAN client 60 does not have to have the standard SMS mobilefunctionality and protocol stack. Instead, the SMS mobile functionalityat the access node 68 would terminate and decode the incoming SMS-MTmessage and send the message content via a secure interface to the SIMenabled WLAN client 60. When the WLAN client 60 wants to send an SMS-MOmessage, the message content will be sent to the access node 68 alongwith its MSISDN and destination phone number. Then the access node 68forms an SMS-MO message on behalf of the WLAN client 60 and transfersthe SMS-MO messages as if it were an SMS mobile itself.

Referring also to FIG. 4, the access node 68 can perform anauthentication procedure 200 to permit the WLAN client 60 to use theWLAN 18. In the present embodiment, the access node 68 includes the SIMcard 110 and a pre-subscription with the mobile network 14 (evidence ofwhich may be stored in the HLR 34) allowing the access node to operateas a mobile station in the mobile network for sending/receiving SMSmessages. In this way, the access node 68 can be authenticated by themobile network 14 for security reason. It is understood that there areadditional ways of authenticating the access node as a subscriber to themobile network, some depending on the type of mobile network andadditional authentication mechanisms that perform similarly to a GSM SIMcard. Also, a voice and/or data subscription may be utilized. Before theaccess node 68 authenticates the WLAN client 60, it identifies itselfand is authenticated as a “trusted” entity by the mobile network 14.

The authentication procedure 200 begins at step 202, where the accessnode 68 sends an Attach Request message including its IMSI in a securelink to the HLR/AuC 34 through the Signaling Gateway 44. At step 204,the HLR/AuC 34 finds an authentication key “Ki” associated with theaccess node's IMSI, selects a random challenge “RAND” and generates anexpected response “XRES” using a GSM authentication algorithm “A3” andthe authentication key Ki. At step 206, the HLR/AuC 34 sends the RAND inan Authentication Request message to the access node 68. At step 208,the access node provides information from the received AuthenticationRequest message to the SIM card 110.

At step 210, the SIM card 110 calculates a Signature Response “SRES” ofthe random challenge RAND, using the same authentication algorithm A3and the same authentication key Ki stored on the SIM card. At step 212,the SIM card 110 sends back the SRES to the access node 68, and at step214 the access node forwards the SRES to the HLR/AuC 34 in anAuthentication Response message.

At step 216, the HLR/AuC 34 compares the received SRES with thegenerated XRES. If the two match, the access node 68 is validated as amobile station on the mobile network 14. At step 218, the HLR/AuC 34sends an Attach Accept message to the access node 68. If at step 216 theSRES and XRES do not match, the HLR/AuC 34 will send an Attach Rejectmessage to the access node 68.

The initial authentication procedure 200 can be combined with otherprocedures, such as with the mobile authentication for SMS services,since they may use the same SIM card. In this case, as soon as theHLR/AuC 34 has authenticated the access node 68, the SMS-mobile module106 (FIG. 2) in the access node will become attached to the mobilenetwork 14.

It is understood that several modifications, changes and substitutionsare intended in the foregoing disclosure and in some instances somefeatures of the invention will be employed without a corresponding useof other features. Accordingly, it is appropriate that the appendedclaims be construed broadly and in a manner consistent with the scope ofthe invention.

1. A method for providing a one-time password (OTP) for accessing awireless local area network (WLAN), the method comprising: sending afirst short messaging service (SMS) message to a mobile stationoperating in a mobile network, the first SMS message including anidentifier for an access node serving the WLAN; receiving a second SMSmessage from the mobile station into the access node; checking for apredetermined attachment condition or a predetermined service conditionassociated with either the mobile station or the mobile network; and ifthe predetermined attachment condition or the predetermined servicecondition is met, providing the OTP to the mobile station.
 2. The methodof claim 1 further comprising: periodically checking for thepredetermined condition while providing a WLAN service to the mobileunit.
 3. The method of claim 1 wherein the OTP is provided to the mobilestation by a third SMS message.
 4. The method of claim 3 wherein themobile network is a GPRS network and the first, second, and third SMSmessages are in a conventional GPRS format.
 5. The method of claim 1wherein the predetermined attachment condition is that the mobilestation be attached to the mobile network while a WLAN service isprovided to a WLAN client.
 6. The method of claim 1 wherein the accessnode is a subscriber of the mobile network and the identifier is anMSISDN number for the access node.
 7. The method of claim 5 wherein theWLAN service is a wireless connection to an internet node.
 8. The methodof claim 7 further comprising: converting messages back and forthbetween a format used by the WLAN and a format used by the internetnode.
 9. A method for providing a one-time password (OTP) to a WLANclient for using a wireless local area network (WLAN), the methodcomprising: receiving an short messaging service (SMS) message from amobile station operating in a wireless network into an access controllerserving the WLAN; checking for a predetermined attachment condition or apredetermined service condition associated with the mobile station; ifthe predetermined attachment condition or the predetermined servicecondition is met, providing the OTP password to the mobile station;receiving an access request from the WLAN client, the access requestincluding the password, wherein the password is provided to one or bothof the mobile station and the WLAN client to enable the WLAN client tooperate in said WLAN; and sending a first SMS message to the mobilestation operating in a mobile network, the first SMS message includingan identifier for an access node serving the WLAN.
 10. The method ofclaim 9 wherein the mobile station and WLAN client are part of a singleunit.
 11. The method of claim 9 further comprising: periodicallychecking for the predetermined attachment condition or the predeterminedservice condition.
 12. The method of claim 9 wherein the password isprovided to the mobile station by another SMS message.
 13. The method ofclaim 9 wherein the step of checking for the predetermined attachmentcondition or the predetermined service condition includes querying ahome location register of the mobile network.
 14. The method of claim 9wherein the step of checking for the predetermined attachment conditionor the predetermined service condition includes connecting to thewireless network by the access controller as a subscriber of thewireless network.
 15. A system configured to perform the method ofclaim
 1. 16. A system configured to perform the method of claim 9.